Discussion Questions are meant to be completed when they are reached in the reading, before continuing.  Getting the "correct" answer to Discussion Questions is not important.  Instead, the purpose of Discussion Questions is to address the issues, start you thinking about the material, and identify your preconceptions.  Completing these assignments before continuing with the reading will aid you greatly in the learning process.
 

Optical fibers carry light from one place to another.  You may have seen toys, such as the revolving wand shown on the left, or home décor items that use optical fibers.  One of the most important applications of optical fibers is in information systems.  Optical fibers carry data that has been encoded into light pulses, keeping the beam of light together so no information is lost.  This data can be computational information sent from one computer to another, video feed from inside someone's body during laparoscopic surgery, or the cable television signal coming to your home.

The simplest optical fiber is a tube of glass or plastic, such as the blue tube shown to the right.  Suppose you shine a laser beam into the left end of the fiber.  Do you think any of the light would escape the straight part of the fiber when you shine light down it, or would all of the light travel through the tube all the way to the bend?  What happens at the bend in the fiber?  Will light escape there? Is there anything special one might do to ensure the light would travel the length of the curved tube without it all escaping? Modern optical fibers have at least two cylindrical layers glass or plastic, with slightly different indices of refraction.  Fibers like this are much more difficult to make than the single-layer fiber illustrated to the right.  Discuss the ramifications of having more than one transparent layer. Which layer (inner or outer) of such a fiber should have the lower index of refraction?  Use Snell's Law to explain why this is the case.

How is the function of optical fibers related to refraction? Continue to the next page to find out!